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/*
* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
*
* Copyright (C) 2002-2011 Aleph One Ltd.
* for Toby Churchill Ltd and Brightstar Engineering
*
* Created by Charles Manning <charles@aleph1.co.uk>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
/* Summaries write the useful part of the tags for the chunks in a block into an
* an array which is written to the last n chunks of the block.
* Reading the summaries gives all the tags for the block in one read. Much
* faster.
*
* Chunks holding summaries are marked with tags making it look like
* they are part of a fake file.
*
* The summary could also be used during gc.
*
*/
#include "yaffs_summary.h"
#include "yaffs_packedtags2.h"
#include "yaffs_nand.h"
#include "yaffs_getblockinfo.h"
#include "yaffs_bitmap.h"
/* Summary tags don't need the sequence number because that is redundant. */
struct yaffs_summary_tags {
unsigned obj_id;
unsigned chunk_id;
unsigned n_bytes;
};
static void yaffs_summary_clear(struct yaffs_dev *dev)
{
if(!dev->sum_tags)
return;
memset(dev->sum_tags, 0, dev->chunks_per_summary *
sizeof(struct yaffs_summary_tags));
}
int yaffs_summary_init(struct yaffs_dev *dev)
{
int sum_bytes;
int chunks_used; /* Number of chunks used by summary */
sum_bytes = dev->param.chunks_per_block *
sizeof(struct yaffs_summary_tags);
chunks_used = (sum_bytes + dev->data_bytes_per_chunk - 1)/
dev->data_bytes_per_chunk;
dev->chunks_per_summary = dev->param.chunks_per_block - chunks_used;
dev->sum_tags = kmalloc(sizeof(struct yaffs_summary_tags) *
dev->chunks_per_summary, GFP_NOFS);
dev->gc_sum_tags = kmalloc(sizeof(struct yaffs_summary_tags) *
dev->chunks_per_summary, GFP_NOFS);
if(!dev->sum_tags || !dev->gc_sum_tags) {
kfree(dev->sum_tags);
kfree(dev->gc_sum_tags);
return YAFFS_FAIL;
}
yaffs_summary_clear(dev);
return YAFFS_OK;
}
void yaffs_summary_deinit(struct yaffs_dev *dev)
{
kfree(dev->sum_tags);
dev->sum_tags = NULL;
kfree(dev->gc_sum_tags);
dev->gc_sum_tags = NULL;
dev->chunks_per_summary = 0;
}
static int yaffs_summary_write(struct yaffs_dev *dev, int blk)
{
struct yaffs_ext_tags tags;
u8 *buffer;
u8 *sum_buffer = (u8 *)dev->sum_tags;
int n_bytes;
int chunk_in_nand;
int chunk_in_block;
int result;
int this_tx;
struct yaffs_block_info *bi = yaffs_get_block_info(dev, blk);
buffer = yaffs_get_temp_buffer(dev);
n_bytes = sizeof(struct yaffs_summary_tags) * dev->chunks_per_summary;
memset(&tags, 0, sizeof(struct yaffs_ext_tags));
tags.obj_id = YAFFS_OBJECTID_SUMMARY;
tags.chunk_id = 1;
chunk_in_block = dev->chunks_per_summary;
chunk_in_nand = dev->alloc_block * dev->param.chunks_per_block +
dev-> chunks_per_summary;
do {
this_tx = n_bytes;
if (this_tx > dev->data_bytes_per_chunk)
this_tx = dev->data_bytes_per_chunk;
memcpy(buffer, sum_buffer, this_tx);
tags.n_bytes = this_tx;
result = yaffs_wr_chunk_tags_nand(dev, chunk_in_nand,
buffer, &tags);
if (result != YAFFS_OK)
break;
yaffs_set_chunk_bit(dev, blk, chunk_in_block);
bi->pages_in_use++;
dev->n_free_chunks--;
n_bytes -= this_tx;
sum_buffer += this_tx;
chunk_in_nand++;
chunk_in_block++;
tags.chunk_id++;
} while (result == YAFFS_OK && n_bytes > 0);
yaffs_release_temp_buffer(dev, buffer);
if (result == YAFFS_OK)
bi->has_summary = 1;
return result;
}
int yaffs_summary_read(struct yaffs_dev *dev,
struct yaffs_summary_tags *st,
int blk)
{
struct yaffs_ext_tags tags;
u8 *buffer;
u8 *sum_buffer = (u8 *)st;
int n_bytes;
int chunk_id;
int chunk_in_nand;
int chunk_in_block;
int result;
int this_tx;
struct yaffs_block_info *bi = yaffs_get_block_info(dev, blk);
buffer = yaffs_get_temp_buffer(dev);
n_bytes = sizeof(struct yaffs_summary_tags) * dev->chunks_per_summary;
chunk_in_block = dev->chunks_per_summary;
chunk_in_nand = blk * dev->param.chunks_per_block +
dev->chunks_per_summary;
chunk_id = 1;
do {
this_tx = n_bytes;
if(this_tx > dev->data_bytes_per_chunk)
this_tx = dev->data_bytes_per_chunk;
result = yaffs_rd_chunk_tags_nand(dev, chunk_in_nand,
buffer, &tags);
if (tags.chunk_id != chunk_id ||
tags.obj_id != YAFFS_OBJECTID_SUMMARY ||
tags.chunk_used == 0 ||
tags.ecc_result > YAFFS_ECC_RESULT_FIXED ||
this_tx != tags.n_bytes)
result = YAFFS_FAIL;
if (result != YAFFS_OK)
break;
if (st == dev->sum_tags) {
/* If we're scanning then update the block info */
yaffs_set_chunk_bit(dev, blk, chunk_in_block);
bi->pages_in_use++;
}
memcpy(sum_buffer, buffer, this_tx);
n_bytes -= this_tx;
sum_buffer += this_tx;
chunk_in_nand++;
chunk_in_block++;
chunk_id++;
} while (result == YAFFS_OK && n_bytes > 0);
yaffs_release_temp_buffer(dev, buffer);
if (st == dev->sum_tags && result == YAFFS_OK)
bi->has_summary = 1;
return result;
}
int yaffs_summary_add(struct yaffs_dev *dev,
struct yaffs_ext_tags *tags,
int chunk_in_nand)
{
struct yaffs_packed_tags2_tags_only tags_only;
struct yaffs_summary_tags *sum_tags;
int block_in_nand = chunk_in_nand / dev->param.chunks_per_block;
int chunk_in_block = chunk_in_nand % dev->param.chunks_per_block;
if(!dev->sum_tags)
return YAFFS_OK;
if(chunk_in_block >= 0 && chunk_in_block < dev->chunks_per_summary) {
yaffs_pack_tags2_tags_only(&tags_only, tags);
sum_tags = &dev->sum_tags[chunk_in_block];
sum_tags->chunk_id = tags_only.chunk_id;
sum_tags->n_bytes = tags_only.n_bytes;
sum_tags->obj_id = tags_only.obj_id;
if(chunk_in_block == dev->chunks_per_summary - 1) {
/* Time to write out the summary */
yaffs_summary_write(dev, block_in_nand);
yaffs_summary_clear(dev);
yaffs_skip_rest_of_block(dev);
}
}
return YAFFS_OK;
}
int yaffs_summary_fetch(struct yaffs_dev *dev,
struct yaffs_ext_tags *tags,
int chunk_in_block)
{
struct yaffs_packed_tags2_tags_only tags_only;
struct yaffs_summary_tags *sum_tags;
if(chunk_in_block >= 0 && chunk_in_block < dev->chunks_per_summary) {
sum_tags = &dev->sum_tags[chunk_in_block];
tags_only.chunk_id = sum_tags->chunk_id;
tags_only.n_bytes = sum_tags->n_bytes;
tags_only.obj_id = sum_tags->obj_id;
yaffs_unpack_tags2_tags_only(tags, &tags_only);
return YAFFS_OK;
}
return YAFFS_FAIL;
}
void yaffs_summary_gc(struct yaffs_dev *dev, int blk)
{
struct yaffs_block_info *bi = yaffs_get_block_info(dev, blk);
int i;
if (!bi->has_summary)
return;
for (i = dev->chunks_per_summary; i < dev->param.chunks_per_block; i++) {
if( yaffs_check_chunk_bit(dev, blk, i)) {
yaffs_clear_chunk_bit(dev, blk, i);
bi->pages_in_use--;
dev->n_free_chunks++;
}
}
}
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